In December 2009, the Tampa-area mother felt like she couldn't put it off any longer and took her daughter, Danielle, to get the shot.

The shot was the first in a series of what should have been three doses of the quadrivalent human papillomavirus vaccine, better known as Gardisil.

Merck Pharmaceuticals was first approved by the Food and Drug Administration in 2006 to use Gardisil in females ages 9 to 26.

Merck's research had shown the vaccine to prevent HPV types 16 and 18, which are the cause of about 70 percent of all cervical cancers, as well as types 6 and 11, which are responsible for genital warts.

According to the Centers for Disease Control, HPV is the most common sexually transmitted disease in the United States, with an estimated 6.2 million people being infected each year.

Of those infections, about 500,000 worldwide will develop into cervical cancer, and even fewer have the potential of developing into vaginal, vulvar, anal or penile cancer.

The latter cancers prompted Merck to gain approval for Gardisil for use in boys in 2009.

When Danielle Tomoser went to get her second dose of the vaccine, her older brother Chad ended up getting his first dose.

Less than three weeks after Danielle's second shot and Chad's first, she experienced a seizure.

"Her brother and father found her on the floor with urine on the floor. Her face was beat up," described Theresa Tomoser.

The seizure had been so violent, and the bruising so unexpected, that the Department of Children of Families opened an investigation into the Tomoser family.

The state eventually dropped the case after a neurological exam confirmed that Danielle had experienced a grand mal seizure, also known as a tonic-clonic seizure.

Tomoser said the doctors offered little to no explanation behind what happened to the otherwise healthy teenager. Tomoser said there was no history of seizures in their family.

Two months later, she answered a call from Chad's school explaining that he had also experienced a grand mal seizure.

"When Chad had his first seizure just 83 days after the shot and Danielle's seizure was 85 days after the shot, that's when I knew it had to be the Gardisil," said Tomoser.

Danielle only experienced one seizure but suffered from what doctors called sleep paralysis on several occasions. Her mother said she would wake up from time to time with bruised and bitten lips.

Chad ended up having multiple seizures over the next year until a neurologist was finally able to control the condition with medication. But some of those medications made the teen depressed to the point that he said he contemplated taking his own life.

"Before this happened I was playing football, baseball, hanging out at school with friends all of the time, and all of a sudden it was like my life was almost over. I couldn't do anything," said the now 21-year-old college senior, who is still not permitted to drive due his medication.

Despite the coincidental timeframe, the Tomosers said no one in the medical community would directly link the seizures to the Gardisil shot.

In fact, the FDA's safety information for the vaccine lists syncope, which is a form of fainting or paralysis, with clonic-tonic jerking and a seizure-like activity as a possible side effect. It falls short of specifically naming seizures.

In the FDA's vaccine adverse event reporting system, seizure cluster, seizure anoxic, clonic-tonic convulsions and seizure like phenomenon have been reported 75 times since Gardisil become available through March 2014.

In total, the FDA has catalogued 31,015 adverse events in VAERS, with 127 indicating death and another 556 categorized as life-threatening.

As of March 2013, the Department of Health and Human Services paid 49 claims totaling $5,877,710.87 for HPV vaccines as part of the government's vaccine injury compensation program.

In Japan, the reports of adverse events were enough for the Ministry of Health to remove its proactive recommendation for the vaccine last June while the adverse events are investigated further.

But according to the FDA, the events listed in the database are not necessarily directly linked with any vaccine.

"People have put a timeline to them and said that they are biologically plausible, but we can't say for sure if they did or didn't happen directly because of the vaccine," said Dr. Diane Harper, the department chair of family and geriatric medicine at the University of Louisville.

Harper was part of a team of independent researchers who ran the clinical trials for Merck before Gardisil's approval.

Since then, Harper has become an outspoken opponent about the drug, appearing in several nationally televised interviews to warn parents to do their research before deciding to inject their children.

Her main complaint, though, is not in regard to the potential side effects, it is regarding the effectiveness of the vaccine.

According to Harper, Merck does not have enough evidence to suggest that Gardisil will protect against HPV for longer than five years. She said Merck knew this after its initial research but fast-tracked the drug for marketing anyways.

"They knew that they were defective. They knew that they were limited and their vaccine had very little cross protection to other types," she said.

A study from 2010 suggests that Gardisil's protection against HPV 18 wanes after four years, but according to a Merck representative, the drug has been proven effective up to eight years.

But Harper contends Merck is bringing about their next generation HPV vaccine, the experimental V503, because they needed to develop some type of booster shot for the original vaccine. She said the drug maker will gloss over the shortcomings of Gardisil by promoting the new vaccine with additional HPV protections. V503 has been being researched since 2007 and is now in the third phase of clinical studies.

Although the FDA would not comment on its approval process of this drug, a Merck representative said the company anticipates U.S. regulatory action within the next year.

Harper's main concern is the number of antigens in the new vaccine.

She pointed out the GaloxoSmithKline drug Cervarix, which guards against the main two cancer-causing strains of HPV and has far less antigens than both Gardisil and V503.

In an email, a Merck representative said the new drug will guard against 90 percent of cancer-causing HPV types, as well as 80 percent of high-grade cervical dysplasias and also some vaginal, vulvar and anal cancers.

"When one thinks about the ability to prevent a disease from happening, which is what we'd love for all of our loved ones, I think the more we can do in that arena, the better off we'd be as a society," said Dr. Veronica Schimp, the chief gynecological oncologist at the University of Florida Cancer Center at Orlando Health.

Schimp is a proponent of the Gardisil vaccine and pointed out that Cervarix has not been approved in boys.

The idea of a new vaccine that would guard against even more types of HPV excited her.

"The way women die from cervix cancer is very painful, it's very difficult to watch and as health-care providers, if you can prevent a cancer from happening, why wouldn't you?" she said.

One way to prevent not just cervical but all gynecological cancers is yearly pap smears and gynecological exams.

Harper said women who are getting HPV vaccinations are less likely to show up for those exams.

She pointed out studies done in the United Kingdom and Australia, where large-scale vaccination programs were implemented.

"Less than half of the women who have been vaccinated show up for pap screening at an age-appropriate time, and that's concerning," she said.

For decades, doctors had been performing Loop Electosurgical Excision Procedures on women with abnormalities in their cervix.

A paper authored by two researches at the University of British Columbia criticized the FDA's fast -rack marketing of HPV vaccines, claiming they are neither more effective nor safe that pap screening and LOOP at preventing cervical cancer.

" All that the HPV vaccines have been proven to reduce is HPV infections and pre-cancerous cervical cancer lesions, a large fraction of which self-resolve without any treatment. As of today, we do not know if the HPV vaccines can actually prevent cervical cancer or simply postpone it," said Lucia Tomljenovi, one of the authors of the 2011 paper.

According to Schimp, the cancers that the vaccines prevent do not generally happen until women are 45 to 55 years old.